The notion of line or straight line was introduced by ancient mathematicians to represent straight objects with negligible width and depth. Lines are an idealization of such objects. Until the seventeenth century, lines were defined like this: "The line is the first species of quantity, which has only one dimension, namely length, without any width nor depth, and is nothing else than the flow or run of the point which 1 will leave from its imaginary moving some vestige in length, exempt of any width. 2 The straight line is that which is equally extended between its points"

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LINE is a close quarters combat system, derived from various martial arts, used by the United States Marine Corps between 1989 and 1998, and then from 1998 through to 2007 for the US Army Special Forces. It was developed by retired combat-arms Marine Ron Donvito.

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  1. A path through two or more points (compare ‘segment); a continuous mark, including as made by a pen; any path, curved or straight.
    The arrow descended in a curved line.
  1. An infinitely extending one-dimensional figure that has no curvature; one that has length but not breadth or thickness.
  2. A line segment; a continuous finite segment of such a figure.
  3. An edge of a graph.
  4. A circle of latitude or of longitude, as represented on a map.
  5. The equator.
    1. One of the straight horizontal and parallel prolonged strokes on and between which the notes are placed.
  6. The horizontal path of a ball towards the batsman (see also length).
  7. The goal line
  8. A rope, cord, string, or thread, of any thickness.
  9. A hose.
  1. Direction, path.
    the line of sight or the line of vision
  2. The wire connecting one telegraphic station with another, a telephone or internet cable between two points: a telephone or network connection.
    I tried to make a call, but the line was dead.
    a dedicated line
    a shared line
    Please speak up, the line is very faint.
  3. A letter, a written form of communication.
    Drop me a line.
  4. A connected series of public conveyances, as a roadbed or railway track; and hence, an established arrangement for forwarding merchandise, etc.
    a line of stages
    an express line
  5. A trench or rampart, or the non-physical demarcation of the extent of the territory occupied by specified forces.
  6. The exterior limit of a figure or territory: a boundary, contour, or outline; a demarcation.
  7. A long tape or ribbon marked with units for measuring; a tape measure.
  8. A measuring line or cord.
  9. That which was measured by a line, such as a field or any piece of land set apart; hence, allotted place of abode.
  10. A threadlike crease or wrinkle marking the face, hand, or body; hence, a characteristic mark.
  11. Lineament; feature; figure (of one's body).
  12. A more-or-less straight sequence of people, objects, etc., either arranged as a queue or column and often waiting to be processed or dealt with, or arranged abreast of one another in a row (and contrasted with a column), as in a military formation.
    The line forms on the right.
    There is a line of houses.
  13. The regular infantry of an army, as distinguished from militia, guards, volunteer corps, cavalry, artillery etc.
  14. A series or succession of ancestors or descendants of a given person; a family or race; compare lineage.
  15. A small amount of text. Specifically:
    1. a written or printed row of letters, words, numbers or other text, especially a row of words extending across a page or column, or a blank in place of such text.
      The answer to the comprehension question can be found in the third line of the accompanying text.
    2. a verse (in poetry).
      1. a sentence of dialogue, especially in a play, movie or the like.
He was perfecting his pickup lines for use at the bar.
"It is what it is" was one his more annoying lines.
  1. a lie or exaggeration, especially one told to gain another's approval or prevent losing it.
Don't feed me a line!
  1. Course of conduct, thought, occupation, or policy; method of argument; department of industry, trade, or intellectual activity.
  2. The official, stated position (or set of positions) of an individual or group, particularly a political or religious faction.
    Remember, your answers must match the party line.
  3. The products or services sold by a business, or by extension, the business itself.
    line of business, product line
    How many buses does the line have?
    The airline is in danger of bankruptcy.
  4. A number of shares taken by a jobber.
  5. A measure of length:
    1. equal to one twelfth of an inch.
      1. equal to one fortieth of an inch.
  6. Alternative name for a maxwell, a unit of magnetic flux.
  7. The batter’s box.
  8. The position in which the fencers hold their swords.
  9. Proper relative position or adjustment (of parts, not as to design or proportion, but with reference to smooth working).
    the engine is in line / out of line
  10. A small portion or serving (of a powdery illegal drug).
  11. Instruction; doctrine.
  12. The proper relative position or adjustment of parts, not as to design or proportion, but with reference to smooth working.
    The engine is in line or out of line.

Noun (etymology 2)

  1. Flax; linen, particularly the longer fiber of flax.


  1. To place (objects) into a line (usually used with "up"); to form into a line; to align.
    to line troops
  2. To place persons or things along the side of for security or defense; to strengthen by adding; to fortify.
    to line works with soldiers
    • 1599 — , , ii 4
      Line and new repair our towns of war With men of courage and with means defendant.
  3. To form a line along.
  4. To mark with a line or lines, to cover with lines.
    to line a copy book
  5. To represent by lines; to delineate; to portray.
    • 1598 — , , iii 2
      All the pictures fairest lined Are but black to Rosalind.
  6. To read or repeat line by line.
    to line out a hymn
  7. To form or enter into a line.
  8. To hit a line drive; to hit a line drive which is caught for an out. Compare fly and ground.

Verb (etymology 2)

  1. To cover the inner surface of (something), originally especially with linen.
  2. To reinforce (the back of a book) with glue and glued scrap material such as fabric or paper.
  3. To fill or supply (something), as a purse with money.

Verb (etymology 3)

  1. to copulate with, to impregnate.

The above text is a snippet from Wiktionary: line
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